A customer called complaining that the car would crank, but would not start (video). When I asked her what happened, she told me that she parked the car, and came back about 30 minutes later. When she tried to start the car, it would not start, and the green key indicator started flashing on the instrument panel. I told her to not bother trying to start the car and to have it towed to our shop.
When the car arrived, we did all the necessary on-hand tests and procedures to diagnose the issue. Everything checked out fine, except no fuel, so we hooked up the scanner and tried to pull codes, but unfortunately - we could not pull any codes out of the ECU (Engine Control Unit). From experience I figured that it must be either the TRANSPONDER or ECU that could make the car crank over and not start while the Green Key security indicator is flashing on the dashboard. I know that older model Hondas had a main relay burning issue, but that was not the case here.
So I notified the customer that we have two possible reasons why the car would not start. First possible reason, and the least expensive, is the need to change the transponder located on top the ignition switch. The transponder is an electronic ring that goes around the ignition switch and reads the signal from the chip key. From there it sends the command to the ECU that it is the correct key, and to send power to the fuel pump. After installing a new transponder, we needed to reprogram the key. Unfortunately, the key that came with the car was severely damaged, disabling us from using it, causing us to cut two new keys.
Let’s step back for a moment… I forgot to tell you that we tried to program the new cut keys with the old transponder, but we were unable to do it. That is how we figured out that we needed a new transponder to make it work.
Installing a new TRANSPONDER and programming the newly cut keys solved the problem. The car started right up and everything went back to normal.